Prevalence of specific allergic diseases in school children as related to parental atopy

Background: Our objective was to investigate the influence of parental alle rgy on the manifestations and course of allergic disease in children. Methods and Results: A total of 15 234 school children aged 6 and 9 years w ere evaluated by means of questionnaires completed by their parents in a cr oss-sectional survey conducted in Tokushima, Japan. The prevalence and rela tive risk ratio (RRR) for parental allergy in children with atopic dermatit is, asthma and allergic rhinitis were 6.4% (RRR 2.5), 3.2% (RRR 2.4) and 15 % (RRR 2.4), respectively The risk of atopic dermatitis was particularly hi gh in children whose parent had atopic dermatitis, with an RRR of 2.8 (fath er) and 3.7 (mother). Children with a parental history of asthma also had a high risk of that disorder (RRR of father 5.3, mother 6.2). However, the r isk of allergic rhinitis was no different in children with a parental histo ry of allergic rhinitis or from children with a parental history of asthma and atopic dermatitis. A history of allergic disease in both parents, espec ially of asthma and atopic dermatitis, increased the risk of allergic disea se in the child. Milder symptoms, such as wheezy bronchitis, in schoolchild ren were similarly related with the same hereditary tendency as the identic al allergic disease. The disappearance of allergic symptoms with age also r elated to a hereditary component, being less likely in children with a hist ory of parental allergy than in those without such an atopic history. Conclusions: The manifestations and course of allergic disease in school ch ildren relate to parental allergic disease.